1. Field of the Invention
The present invention relates to processing of a color image, and more particularly, to a method and an apparatus to enhance a local luminance of an image, and a computer-readable recording medium to store a computer program.
2. Description of the Related Art
In a conventional image luminance enhancing method, an ineffective luminance display ability of a color image display device may be adjusted or enhanced. The conventional image luminance enhancing method may be categorized into three classes. The conventional image luminance enhancing method belonging to the first class is disclosed in U.S. Pat. No. 5,132,796, entitled “Method and Apparatus for Digitally Processing Gamma Pedestal and Gain,” U.S. Pat. No. 5,255,093, entitled “Apparatus and Method for Limiting Gain in a Digital Gamma Corrector,” and U.S. Pat. No. 6,515,676, entitled “Analog Interface Display Apparatus with Color Display Control.” In the conventional image luminance enhancing method belonging to the first class, parameters to adjust the overall luminance of an output image to be displayed are determined according to the overall luminance characteristic of an input image.
The conventional image luminance enhancing method belonging to the second class is disclosed in U.S. Pat. No. 5,394,195, entitled “Method and Apparatus for Performing Dynamic Gamma Contrast Control.” In the conventional image luminance enhancing method belonging to the second class, parameters to compensate for the overall luminance of an output image to be displayed are determined using information on a portion of an input image, not on a portion of a luminance area of the input image which represents the luminance of the input image.
In the conventional image luminance enhancing methods belonging to the first and second classes, since a luminance of a local area of an input image cannot be compensated for, the overall luminance of the input image cannot be partially enhanced. Since the overall luminance of the input should be compensated for, time taken to compensate for the luminance of the input image is protracted.
The conventional image luminance enhancing method belonging to the third class is disclosed in U.S. Pat. No. 6,414,659, entitled “LCD Gain and Offset Value Adjustment System and Method.” In the conventional image luminance enhancing method belonging to the third class, parameters are adjusted according to the luminance characteristic of a display device regardless of an input signal to compensate for the luminance of an output image to be displayed.
Accordingly, the conventional image luminance enhancing method belonging to the three classes may contribute to preventing a luminance representation ability of a display device from deteriorating due to the characteristics of the display device. However, the ineffective luminance characteristic of an input image cannot be compensated for.